20160412

Online reading assignment: medium-mass stars, massive stars, neutron stars and black holes (NC campus)

Astronomy 210, spring semester 2016
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on the evolution of medium-mass stars, massive stars, neutron stars and black holes.


Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.
"The reason red dwarfs have a longer life span is because they are convective and can use all of their hydrogen to prolong their lifetime."

"Reading about the Hummer and the SmartCar was cool. I guess size doesn't matter?"

"Black holes."

"I didn't know that none of the red dwarfs have died out yet. That's pretty cool that the little guys are the ones that last the longest. It's deep."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"How the process for converting gravitational energy into thermal energy works for protostars."

"So why are black holes so important to learn about?"

"How things blow up."

"Everything, because I missed a week and now I'm really behind."

A Hummer H2 and a SmartCar ForTwo can travel the same distance with a full tank of gas. Briefly explain how this is possible.
"The Hummer, with lower mileage than the SmartCar, would need to have a larger fuel tank."

"Though the SmartCar doesn't use as much gas, it can't hold as much gas as a Hummer H2 can, so they travel the same distance."

"The Hummer H2 gets lower mileage but can hold more gasoline. The SmartCar ForTwo gets better mileage but holds less gasoline. Therefore the differences between the two even out to driving the same distance from full to empty."

Match the end-of-life stage with the corresponding main-sequence star.
(Only correct responses shown.)
Black hole: massive main sequence star [56%]
Neutron star: massive main sequence star [33%]
White dwarf: medium-mass main-sequence star [56%]
(No stellar remnant observed yet: low-mass main-sequence star [11%]

Match the type of explosion (if possible) with the corresponding main-sequence star.
(Only correct responses shown.)
Type II supernova: massive main sequence star: [67%]
Type Ia supernova: medium-mass main-sequence star [67%]
Nova: medium-mass main-sequence star [22%]
Low-mass main-sequence star: (no explosion possible) [33%]

If you were to leap into a black hole, your friends would typically watch you falling in for __________ before you entered the event horizon.
seconds.  ** [2]
hours.  [0]
days.  ** [2]
a year.  [0]
many years.  [0]
forever.  ** [2]
(Unsure/guessing/lost/help!)  *** [3]

The first rule of astronomy class is...
"Be prepared for the unexpected."

"Have fun! Right?"

"I completely forgot...I feel ashamed."

"To show up to astronomy class (wearing a cool space t-shirt)."

"Study and attend class."

"Know what astronomy means."

"You do not talk about astrology."

"You do not talk about astronomy class."

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Well that was a short spring break, but happy to learn about white dwarfs."

"I accidently jumped ahead to the next section, studied it, and was ready to do the online assignment for it. Then I realized I messed up. I am so tired and I apologize for all my 'unsure' answers."

"Did you do anything exciting over spring break?" (Mrs. P-dog and I went to Joshua Tree National Park. It was awesome.)

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